The present invention relates to a technology capable of constructing an RF communication automated material handling system while minimizing structural change for a previously installed optical-communication automated material handling system, by constructing RF communication environment between an automated guided vehicle and manufacturing equipment by using separate communication modules provided in the automated guided vehicle and the manufacturing equipment.
Generally, in manufacturing processes of a liquid crystal display device and a semiconductor element, the manufacturing goods are transferred to the manufacturing equipment of each manufacturing process by using an automated material handling system (AMHS), so that the corresponding goods are manufactured according to the manufacturing processes of each manufacturing equipment. Such an automated material handling system utilizes an unmanned transporting device for transferring a carrier of receiving a semiconductor substrate or a liquid crystal substrate to the manufacturing station located on the manufacturing process line and transferring the carrier of again receiving the goods completely processed in the corresponding manufacturing equipment to the next manufacturing equipment.
Depending on the movement method thereof, the unmanned transporting device includes an automated guided vehicle (AGV) for driving through the wheel, a rail guided vehicle (RGV) for driving along the guide rail located at the bottom, and an overhead hoist transport (OHT) for driving a guide rail installed in the ceiling. These unmanned transporting devices are moved to the corresponding manufacturing equipment by using the wheel itself or along the bottom rail or the overhead rail and it carries the carrier onto or carries the carrier out the manufacturing equipment by using an operating arm or a hoist and a hand.
The carrying/carrying out of the carriers is accomplished by the host computers mounted on the unmanned transporting device and the manufacturing equipment under the control of the main controller for controlling the entire manufacturing lines. At this time, since it requires the interlock operation between the unmanned transporting device and the manufacturing equipment during the carrying/carrying out of the carrier, transmission devices of an optical communication mode using an IR (Infrared) are installed on the unmanned transporting device and the manufacturing equipment respectively so as to send and receive the necessary data, thereby smoothly performing the carrying/carrying out of the carriers.
FIG. 1 is a schematic diagram illustrating a communication system for automated material handling system using a conventional IR optical communication. In the practice of the communication using this way, there is a disadvantage in that communication units between an unmanned transporting device and a manufacturing equipment should be installed in close proximity as possible. Accordingly, in order to communicate with the unmanned transporting device installed on the ceiling using the IR optical communication, the communication unit of the manufacturing equipment must be installed on the ceiling in like manner.
Owing to this installation constraint, the cable of the communication unit for facility should be installed along the ceiling having above 5 m height. Also, it has difficulty in the beauty and management inside the plant. Moreover, since it sends and receives the communication without the generation of a unique ID, the communication interference between adjacent communication devices can be generated due to the optical noise.
Where it replaces the IR optical communication module with the RF (Radio-Frequency) communication module so as to overcome the above drawbacks, since the data is transmitted through the ID, it can avoid the problem of the interference. Also, although the communication unit for equipment is not installed on the ceiling, the communication between the unmanned transporting device and the manufacturing equipment can be made.
FIG. 2 is a schematic diagram illustrating a communication system for automated material handling system using a conventional RF communication. In this RF communication method, since each manufacturing equipment should be given a unique ID, the unmanned transporting device recognizes the corresponding ID for manufacturing equipment and communication channel information and then, it should be set for RF communication module in the unmanned vehicle controller, so that the communication between the unmanned transporting device and the manufacturing equipment can be made. At this time, the corresponding ID and the communication channel information are inputted to the communication modules of each manufacturing equipment in advance.
As shown in FIG. 3, the unmanned transporting device is provided with both of IR communication module and RF communication module, so that the automated material handling system is capable of selectively utilizing the optical communication method and the RF communication method has been proposed. In this communication method, any one of the optical communication method and the RF communication method can be selectively utilized so as to minimize the data transmission error owing to the surrounding environment in response to the position of the manufacturing equipment.
However, the automated material handling system using the conventional optical communication method is already established in the factory or it tries to establish a new automated material handling system using the RF communication method shown in FIG. 2 and FIG. 3. Since the communication module has never had the ID setting function in automated material handling system using the conventional IR optical communication method, even structure of the unmanned vehicle controller of the unmanned transporting device should be changed over all during the replacement of communication module (IR mode→RF mode) or the addition thereof (IR mode→IR mode+RF mode) so as to provide the ID setting function.
That is, as shown in FIG. 1, in the IR optical communication method, only input and output terminals are connected between the unmanned vehicle controller of the unmanned transporting device and the communication module. However, as shown in FIG. 2 and FIG. 3, since it performs the ID and channel setting through the serial terminal in the RF communication method, the unmanned vehicle controller of the unmanned transporting device should be newly developed.
Thus, in order to change the automated material handling system using the conventional optical communication method to the automated material handling system using the RF communication method, since the unmanned transporting device should be changed or replaced over all, the facility lines should be suspended for a number of years. Accordingly, there are problems in that a lot of time and cost and an inconvenience of a user are involved.    Patent Literature 1: Korean Patent Registration No. 10-1527686 (Jun. 3, 2015; Title: Data Transmission System For Automated Material Handling System)    Patent Literature 2: Korean Patent Registration No. 10-1616706 (Apr. 25, 2016; Title: RF Communication System And Method For Automated Material Handling System)